The best IWB for this position that I have found is the Alessi MOB. It holds with one of his Talon Clips, just behind the trigger guard. This clip goes on the waistband, and under the belt. I've carried a SIG P220 and a S&W 4516 through several summers with good comfort and concealment. The position, on the spine, is a no-no. I've spent some 26 months in a wheelchair, and still walk with a cane, over some spinal cord problems. I don't want to go there, no mo'. I wear this rig toward the strong side, about 4:30ish, with the clip just to the side of the 6:00 belt loop (or back center seam). The "big butted" SIG concealed very well, as the extreme rake, meant for MOB position, kicks the butt high and farther forward, so that it is hard to get it to print. The flatter 4516 is even better. This position is far enough back that I can reach the gun with either hand, and comfortable enough for long term wear. Our humidity is light years higher than in AZ, but I treat all of my IWBs with either Kiwi Camp Dry (non-silicone) or a Sno Seal leather waterproofer called Silicone Water Guard. Three summers of wear with the SIG (and daily wipes at the end of the day) and no rust, even on the grip screws. The holster adds only two thicknesses of leather to the gun, is smooth side out so it doesn't "gather shirt tail", and the extra cant also keeps the muzzle off the tender back muscles when driving or seated for long periods. I no longer think of them as "MOB" holsters - Just darned good stongside IWBs, worn a little farther back.